Imagine stubbing your little toe on the leg of a table. Imagine getting your finger caught in a door as it closes. Imagine—okay, it’s actually starting to hurt to imagine now. Point being: you know what pain is. But an Italian woman, her two daughters and three grandchildren, do not.
And now, team of researchers from Britain have figured out why. Apparently, the family have no thermoception, which means they can’t sense temperature, whether hot or cold.
The scientists decided to test the family, as well as some mice, by poking them in tender points, having them touch hot surfaces, and dunking their hands in ice water. Nothing really happened, besides their skin getting a little red or wet.
“Genetic analysis of a human family with Marsili syndrome, a rare and perhaps unique inherited pain insensitive phenotype, and mouse modelling have shown ZFHX2 as a critical gene for normal pain perception,” the authors said in the study, published recently in the journal Brain. The syndrome Marsili is named after this family.
Then the researchers sequenced part of the family’s genomes, and discovered a new mutation in the ZFHX2 gene. This gene alters how nociceptors — the pain-sensing part of the nerve cells that turn external inputs into stimuli for the brain — translate DNA code into protein-making instructions.
Previous research has actually created mice without that ZFHX2 gene, and those mice turned out to be more hyperactive and showed signs of depression. In this new study, the ZFHX2-altered mice had difficulty sensing hot and cold, suggesting that the mutation in the gene is what causes the family’s lack of pain.
The finding could open the way for better treatments and medicines for people with chronic pain. Over 1.5 billion people in the world suffer from chronic pain, and many more suffer from conditions or circumstances that cause them an array of different kinds of pain.
Genetic mutations are the driving force of evolution. Evolution happens when a mutation is successful enough to be passed through generations and generations of a species, eventually making that mutation the norm.
And though you might like the idea of not feeling pain — the Italian family themselves are happy with their mutation — I’m not sure in the long run you would want that. Unless you really really wanted to slap yourself.
Pain is a signal that something is wrong with your body. Without it, you won’t necessarily know if you need to go to the hospital or not. That could be deadly. After all, painlesssness doesn’t make you immortal.
But maybe there’s a mutation for that too.